Pattern of adverse drug reactions experienced by tuberculosis patients in a tertiary care teaching hospital in western Nepal

Tuberculosis is a common problem in developing countries including Nepal. Data regarding the safety profile of anti tubercular drugs is lacking in Nepal. The present study analyzed the pattern of ADRs caused by the antitubercular drugs. Inpatient files of all the TB patients who received treatment at the Manipal Teaching Hospital, Pokhara, Nepal during the period from 1(st) January 2001 till 31(st) December 2006 were taken. Altogether 326 patients were identified among which 40 (females 24, males 16) experienced at least one ADR (incidence 12.27%). The mean +/- SD age of the patients was 42.12 +/- 20.41 years. The most common ADR was elevated liver enzymes [24 (57.14%)] and hepatobiliary system was the most common system affected [24 (58.5%)]. More than half the ADRs [21 (52.55%)] developed with in 20 days of initiation of therapy. Isoniazid and pyrazinamide were the suspected drugs responsible for 32.32% each of the total ADRs. The mean SD of the total number of drugs used in the patients were 4.77 +/- 1.46. The most common laboratory abnormality observed was elevated SGOT level [21 patients (52.5%)]. Seven (17.5%) patients needed specific drug treatment for managing the ADRs and 10 (25%) needed symptomatic management. Thirty five (87.5%) patients recovered following the ADR. Multiple drug therapy was the reason behind the development of 30 (75%) ADRs. It was found that 29 (72.5 %) ADRs were 'probably' due to the suspected drugs. Majority [19(47.5 %)] of the ADRs were mild [level (1)]. This study shows that ADRs to anti tubercular drugs are common. Since TB is a common problem in Nepal, special efforts are needed to tackle the drug related complications associated with ATT drugs.